Dave,
my experience of MOT advisories is that are as useful as "Party Political Broadcasts" in that they reflect the particular interest of the person at the time.
My son's BMW gets an advisory every year if he takes it to the local "do everything" MOT garage. The BMW dealer he took it to said "they don't know BMWs, that is what they do. No advisory, no work needed and re-issued it with a new MOT without advisories.
For the MOG I'd only use a MOT tester that either specialised in old cars or Morgans. There are so many "special MOG Features!!
I use a local branch of a national chain of tyre suppliers in Worcester. The guy's a darling: I explain what I've done to the car over the winter and then he tests it; he always asks my opinion if he thinks something might have too much play in it, then if the allotted time isn't used up, he makes me a nice cup of tea before passing it.
